Technical Field
The present invention relates to a method for manufacturing a three-dimensional shaped object and a three-dimensional shaped object.
Related Art
A technology in which a three-dimensional object is formed by solidifying power by using coupling liquid is well-known (see Japanese Laid-open Patent Application Publication No. 6-218712 as an example). In this technology, the following operations are repeated to form the three-dimensional object. Initially, a powder layer is formed by thinly spreading the powder with uniform thickness, and the power is coupled by ejecting the coupling liquid in a desired part of the powder layer. As a result, the powder is coupled in only the part of the powder layer where the coupling liquid was ejected, and a thin plate-shaped member (hereinafter referred to as “cross-section member”) is formed. After that, on the powder layer, an additional powder layer is thinly formed, and the coupling liquid is ejected to the desired portion. As a result, in the portion of the newly formed powder layer where the coupling liquid was ejected, a new cross-section member is also formed. At this point, the coupling liquid ejected on the powder layer penetrates to reach the previously formed cross-section member so that the newly formed cross-section member is bonded to the previously formed cross-section member. By repeating such operations, the thin plate-shaped cross-section members are laminated one-layer by one-layer so as to form the three-dimensional object.
With such three-dimensional shaped object forming technology, an object can be immediately formed by coupling the powder as long as the three-dimensional shape data of the object to be formed is provided, and it is not required to make a mold for forming the object in advance so that the three-dimensional object can be promptly formed at low cost. Also, a thin plate-shaped cross-section member is laminated one-layer by one-layer to form the object so that even if the object has a complex inner structure, the object can be integrally formed without separating into a plurality of components.
However, the coupling liquid ejected to the powder layer does not directly penetrates from an impact position to the inside of the powder layer so that in a conventional method for manufacturing the three-dimensional shaped object, there is a problem that a part corresponding to the outer surface of each layer of the three-dimensional shaped object is unevenly formed due to the ink spread. Further, there is a problem that by laminating such layers, it causes irregular steps (unevenness) formed on the outer surface of the three-dimensional shaped object.